L. There can be no communion where there is no distinction. But we shall be in an abyss of metaphysics presently, if we don't look out; and besides, we must not be too grand, to-day, for the younger children. We'll be grand, some day, by ourselves, if we must. (The younger children are not pleased, and prepare to remonstrate; but, knowing by experience, that all conversations in which the word "communion" occurs, are unintelligible, think better of it.) Meantime, for broad answer about the atoms. I do not think we should use the word "life," of any energy which does not belong to a given form. A seed, or an egg, or a young animal, are properly called "alive" with respect to the force belonging to those forms, which consistently develops that form, and no other. But the force which crystallizes a mineral appears to be chiefly external, and it does not produce an entirely determinate and individual form, limited in size, but only an aggregation, in which some limiting laws must be observed. MARY. But I do not see much difference, that way, between a crystal and a tree. L. Add, then, that the mode of the energy in a living thing implies a continual change in its elements; and a period for its end. So you may define life by its attached negative, death; and still more by its attached positive, birth. But I won't be plagued any more about this, just now; if you choose to think the crystals alive, do, and welcome. Rocks have always been called "living" in their native place. MARY. There's one question more; then I've done. L. Only one? MARY. Only one. L. But if it is answered, won't it turn into two? MARY. No; I think it will remain single, and be comfortable. L. Let me hear it. MARY. You know, we are to crystallize ourselves out of the whole playground. Now, what playground have the minerals! Where are they scattered before they are crystallized; and where are the crystals generally made? L. That sounds to me more like three questions than one, Mary. If it is only one, it is a wide one. MARY. I did not say anything about the width of it. L. Well, I must keep it within the best compass I can. When rocks either dry from a moist state, or cool from a heated state, they necessarily alter in bulk; and cracks, or open spaces, form in them in all directions. These cracks must be filled up with solid matter, or the rock would eventually become a ruinous heap. So, sometimes by water, sometimes by vapor, sometimes nobody knows how, crystallizable matter is brought from somewhere, and fastens itself in these open spaces, so as to bind the rock together again with crystal cement. A vast quantity of hollows are formed in lavas by bubbles of gas, just as the holes are left in bread well baked. In process of time these cavities are generally filled with various crystals. MARY. But where does the crystallizing substance come from?